Emissions intensity in electricity: which fuel is most efficient?


Emissions intensity refers to the amount of greenhouse gas emissions produced per unit of output, such as per kilowatt-hour (kWh) of electricity generated, per unit of economic output (e.g., GDP), or per unit of product manufactured. It's a measure used to assess the environmental impact of producing energy or goods, indicating how much carbon dioxide (CO2) and other greenhouse gases are emitted for each unit of production.

Lower emissions intensity means that less CO2 is released for the amount of energy produced or economic value generated, signifying a more efficient and environmentally friendly production process. Renewable energy sources like wind, solar, and hydroelectric power stand out for their low emissions intensity.

Coal

Has the highest emissions intensity among traditional energy sources, releasing more CO2 per unit of electricity generated due to its carbon-dense nature.

Natural Gas

Offers a lower emissions intensity compared to coal, emitting about 50-60% less CO2 for the same amount of electricity produced, making it a more efficient fossil fuel option.

Oil

Rarely used for electricity due to its high cost and emissions intensity, producing significant CO2 emissions per unit of electricity generated.

Nuclear

Exhibits very low emissions intensity, as it generates large amounts of electricity with minimal direct CO2 emissions, making it one of the most efficient energy sources in terms of emissions.

Hydroelectric

Features very low emissions intensity, producing a vast amount of electricity with negligible direct CO2 emissions, though potential methane emissions from reservoirs can vary.

Wind

Has an extremely low emissions intensity, generating electricity without direct CO2 emissions and minimal overall lifecycle emissions, making it highly efficient.

Solar

Demonstrates low emissions intensity, with the bulk of emissions coming from manufacturing processes, but still provides efficient electricity generation with minimal direct emissions.

Biomass

Can have variable emissions intensity depending on the biomass source and its management, but is often considered carbon-neutral when sustainably sourced and used.

Geothermal

Offers low emissions intensity, producing electricity with minimal CO2 emissions and high efficiency, especially in areas with rich geothermal resources.

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